/*
 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package org.graalvm.component.installer.persist;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.Properties;

/**
 * Provides sorted properties, for deterministic saves.
 */
public final class SortedProperties extends Properties {

    private static final long serialVersionUID = 1L;

    @Override
    @SuppressWarnings({"rawtypes", "unchecked"})
    public Enumeration<String> propertyNames() {
        return (Enumeration) keys();
    }

    @Override
    @SuppressWarnings({"rawtypes", "unchecked"})
    public synchronized Enumeration<Object> keys() {
        Enumeration<Object> keysEnum = super.keys();
        List<String> keyList = new ArrayList<>();
        while (keysEnum.hasMoreElements()) {
            keyList.add((String) keysEnum.nextElement());
        }
        Collections.sort(keyList);
        return Collections.enumeration((Collection) keyList);
    }
}
